Elastic laminates and process for producing same

ABSTRACT

A method is provided for producing elastic composite laminates. The laminates contain elastic filaments that are stretched and laminated to at least one facing material. The continuous filaments are laminated to the facing material using a starved slot coat process. The starved slot coat process provides various benefits and advantages including the production of laminates having improved properties.

BACKGROUND OF THE INVENTION

Articles requiring a degree of elasticity have been formed by combiningelastic materials with inelastic, or less elastic, materials throughvarious lamination processes. Often, such composite laminate articleswill be stretchable because of the presence of the elastic material andthe particular manner in which the elastic and inelastic materials havebeen bonded together during the laminating process.

Typically, such stretchable laminates are formed by joining theinelastic material to the elastic material while the elastic material orsheet is in a stretched condition. After such joining of the materials,the laminated article is then allowed to relax, which results in theinelastic component gathering in the spaces between bonding sites on theelastic sheet. The resulting laminate article is then stretchable to theextent that the inelastic material gathered between the bond locationsallows the elastic material to elongate. Examples of these types ofcomposite laminate articles and materials are set forth in U.S. Pat.Nos. 4,720,415 and 5,385,775, each of which is incorporated herein byreference thereto.

In some stretchable laminate articles, elastic strands of continuousfilaments are bonded to relatively inelastic sheet materials while theelastic strands are in a stretched condition. Such elastic continuousfilaments may, in certain articles, be sandwiched between two or morerelatively inelastic sheets. The relatively inelastic sheets may includenonwoven webs formed by meltblowing or spunbonding various polymers.Examples of such laminates are shown in U.S. Pat. No. 5,385,775; in U.S.Pat. No. 6,057,024; and in U.S. Published Patent Application No. U.S.2002/0104608, which are all incorporated herein by reference.

As shown in the '775 patent, elastic continuous filaments may beextruded onto a horizontally moving sheet of material. The continuousfilaments are extruded from above the horizontal plane of the sheetmaterial and directly onto the material for bonding thereto. In the '024patent, an alternative embodiment is disclosed in which the continuousfilaments are extruded vertically in a downward direction. As thefilaments are extruded in a downward direction, the filaments arestretched and then laminated to one or more sheet materials.

In many embodiments in the past, an adhesive was used in order to adherethe elastic strands of continuous filaments to the sheet materials. Inone embodiment, for instance, the adhesive was sprayed on the sheetmaterial prior to contacting the filaments. Spraying the adhesivematerial onto the sheet materials, however, may have some drawbacks invarious applications. For instance, spray devices may be difficult tocontrol leading to over-application of the adhesive or leading to anon-uniform coverage of the adhesive on the sheet material, especiallyat high machine speeds and at low application rates. In fact,over-application of a hot adhesive during a spray process may causefilament breakage and machine downtime. Further, since the adhesive hasto travel a distance prior to contacting the sheet material, theadhesives may experience a loss in tack prior to contacting the sheetmaterial.

In view of the above, a need currently exists for an improved method forapplying an adhesive material in between stretched elastic filaments anda nonwoven facing. A need also exists for an elastic composite laminatethat has improved properties due to the manner in which an adhesive isapplied.

SUMMARY OF THE INVENTION

In general, the present disclosure is directed to composite elasticmaterials that include a plurality of elastic continuous filamentsbonded to at least one nonwoven web. The nonwoven web is laminated tothe continuous filaments when the filaments are in a stretched state.Thus, when the filaments are relaxed, the nonwoven web gathers andallows the entire composite to stretch in at least one direction.

The present disclosure is more particularly directed to a method forapplying an adhesive material in between the elastic continuousfilaments and the nonwoven web and is directed to composite nonwovenmaterials produced by the process. The adhesive material is applied tothe nonwoven web using a “starved” slot coating process in which theadhesive is emitted through a slot extrusion die onto the nonwoven webto form a discontinuous coating. The discontinuous coating containsamorphous elements of the adhesive material. The adhesive material isapplied to a surface of the nonwoven web in a substantially uniformmanner in terms of amount per area.

The starved coat process provides various benefits and advantages. Forinstance, the process allows for control over the placement of theadhesive on the nonwoven web. Further, the inventors have discoveredthat the process provides a very efficient use of the adhesive. Inparticular, relatively low amounts of adhesive are used that securelybond the elastic continuous filaments to the nonwoven web, even when theelastic filaments are present in a stretched state. Unexpectedly, thepresent inventors also discovered that the process produces compositenonwoven materials having a reduced porosity in comparison to similarcomposites made in which the adhesive is sprayed on the nonwoven web.The relatively low porosity provides various benefits when the compositematerial is used to construct various articles, such as whenincorporated into absorbent garments including diapers, training pants,swim pants, adult incontinence products, feminine hygiene products,bandages and medical drapes, and the like.

In one particular embodiment, for instance, the present disclosure isdirected to a method for producing a composite nonwoven material. Themethod includes the steps of extruding continuous filaments. Thefilaments comprise an elastomeric material. The elastomeric material mayinclude, for instance, elastic polyesters, elastic polyurethanes,elastic polyamides, elastic copolymers of ethylene and at least onevinyl monomer, elastic metallocene-catalyzed polyolefins, and elasticblock copolymers.

Once formed, the elastic continuous filaments are stretched and thenlaminated to the first side of a nonwoven web. In order to bond thestretched laminates to the nonwoven web, an adhesive material is appliedto the nonwoven web from a slot extrusion die. The adhesive materialforms a discontinuous coating comprising amorphous elements of theadhesive material. The adhesive material may be applied to the firstside of the nonwoven web in an amount less than about 4.4 gsm, such asfrom about 0.5 gsm to about 3 gsm. The adhesive material may comprise,for instance, a styrenic block copolymer, a random copolymer of apolyolefin, or an amorphous polyalphaolefin. In addition to the above,any suitable hotmelt adhesive may be applied in accordance with theteachings of the present disclosure.

During application of the adhesive material to the nonwoven web, thenonwoven web may be configured to contact and slide against the slot onthe slot extrusion die. The adhesive material may contact the web at aviscosity of from 500 cp to about 50,000 cp, such as from about 2,000 cpto about 20,000 cp. The temperature of the adhesive may vary dependingupon the particular adhesive material used. In one embodiment, forinstance, the application temperature of the adhesive may be from about320° F. to about 350° F.

In one embodiment, the method can further include the step of laminatingthe elastic continuous filaments to a second nonwoven web. For example,the continuous filaments may be positioned in between the first nonwovenweb and the second nonwoven web. The second nonwoven web may belaminated to the continuous filaments using an adhesive material asdescribed above.

The nonwoven webs that are laminated to the elastic continuous filamentsmay vary depending upon the particular application and desired result.The nonwoven webs may comprise, for instance, meltblown webs, spunbondwebs, bonded carded webs, and the like. In one embodiment, for instance,the nonwoven web comprises a spunbond web having a basis weight of fromabout 7 gsm to about 100 gsm, such as from about 10 gsm to about 20 gsm.

Other features and aspects of the present invention are discussed ingreater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof to one skilled in the art, is set forth moreparticularly in the remainder of the specification, including referenceto the accompanying figures, in which:

FIG. 1 is a perspective view of one embodiment of a process forproducing composite nonwoven materials in accordance with the presentinvention;

FIG. 2 is a side view of the system and process illustrated in FIG. 1;

FIG. 3 is a partial view of an extrusion surface of an exemplaryextruder head for extruding elastic continuous filaments;

FIG. 4 is a magnified view of a portion of the surface illustrated inFIG. 3;

FIG. 5 is a side view of another embodiment of a process that may beused to form composite nonwoven materials in accordance with the presentinvention;

FIG. 6 is a plan view of one embodiment of a system and process forapplying adhesive materials to nonwoven webs for use in the process ofthe present invention; and

FIG. 7 is a perspective view of one embodiment of a slot extrusion diehead that may be used in the process of the present invention.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present invention.

Definitions

The term “continuous filaments”, as used herein, refers to strands ofcontinuously formed polymeric filaments. Such filaments will typicallybe formed by extruding molten material through a die head having acertain type and arrangement of capillary holes therein.

The term “elastic” or “elasticized”, as used herein, refers to amaterial which, upon application of a biasing force, is stretchable,which is elongatable to at least about 60 percent (i.e., to a stretched,biased length which is at least about 160 percent of its relaxedunbiased length), and which will recover at least 55 percent of itselongation upon release of the stretching force. A hypothetical exampleof an elastic material would be a one (1) inch sample of a materialwhich is elongatable to at least 1.60 inches and which, when released,will recover to a length of not more than 1.27 inches. Many elasticmaterials may be elongated by more than 60 percent (i.e., more than 160percent of their relaxed length). For example, some elastic material maybe elongated 100 percent or more, and many of these will recover tosubstantially their initial relaxed length such as, for example, within105 percent of their original relaxed length upon release of thestretching force.

The term “composite nonwoven fabric”, “composite nonwoven”, “laminate”,or “nonwoven laminate”, as used herein, unless otherwise defined, refersto a material having at least one elastic material joined to at leastone sheet material. In most embodiments such laminates or compositefabric will have a gatherable layer which is bonded to an elastic layeror material so that the gatherable layer may be gathered between bondinglocations. As set forth herein, the composite elastic laminate may bestretched to the extent that the gatherable material gathered betweenthe bond locations allows the elastic material to elongate. This type ofcomposite elastic laminate is disclosed, for example, in U.S. Pat. No.4,720,415 to Vander Wielen et al., which is incorporated herein in itsentirety by reference thereto.

As used herein, the term “nonwoven web” refers to a web having astructure of individual fibers or threads that are interlaid, but not inan identifiable, repeating manner. Nonwoven webs have been, in the past,formed by a variety of processes such as, for example, meltblowingprocesses, spunbonding processes and bonded carded web processes.

As used herein, the term “meltblown fibers” means fibers formed byextruding a molten thermoplastic material through a plurality of fine,usually circular, die capillaries as molten thermoplastic material orfilaments into a high velocity gas (e.g. air) stream which attenuatesthe filaments of molten thermoplastic material to reduce their diameter,which may be to microfiber diameter. Thereafter, the meltblown fibersare carried by the high velocity gas stream and are deposited on acollecting surface to form a web of randomly disbursed meltblown fibers.Such a process is disclosed, for example, U.S. Pat. No. 3,849,241 toButin, which is incorporated herein in its entirety by referencethereto.

As used herein, the term “spunbonded fibers” refers to small diameterfibers formed by extruding a molten thermoplastic material as filamentsfrom a plurality of fine, usually circular, capillaries of a spinerettewith the diameter of the extruded filaments then being rapidly reducedas by, for example, eductive stretching or other well-known spun-bondingmechanisms. The production of spun-bonded nonwoven webs is illustratedin patents such as, for example, U.S. Pat. No. 4,340,563 to Appel etal., and U.S. Pat. No. 3,692,618 to Dorschner et al. The disclosures ofthese patents are incorporated herein in their entireties by referencethereto.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that thepresent discussion is a description of exemplary embodiments only, andis not intended as limiting the broader aspects of the presentinvention.

The present disclosure is generally directed to a method for producing acomposite elastic nonwoven material and to the material itself. Moreparticularly, the present disclosure is directed to a starved slot coatprocess for applying an adhesive to a facing material in order tolaminate the facing material to a plurality of stretched filaments.Through the above process, the adhesive has been found to firmly bondthe elastic filaments in a stretched state to the facing material. Oncerelaxed, the facing material gathers forming a stretchbonded laminatethat has elastic properties in at least one direction.

In one embodiment, during the starved slot coat process, the facingmaterial contacts the slot of the slot extrusion die (or “slot die”) asthe adhesive is applied to the facing. The adhesive is applied to thefacing at relatively low amounts forming a discontinuous coating on thenonwoven material. Even at relatively low adhesive application rates,the process has been found to securely bond the elastic filaments to thefacing without problems of delamination.

In the past, elastic filaments have been laminated to facing materialsby spraying an adhesive onto the facing material, such as disclosed inU.S. Patent Application Publication No. U.S. 2002/0104608. The processof the present disclosure, however, provides many benefits andadvantages in comparison to an adhesive spray process. For example, theslot coat process may allow lamination at higher line speeds and mayproduce laminates having a higher peel strength. Unexpectedly, the slotcoat process also produces laminates having a lower porosity, whichmakes the material easier to handle during later converting processes.It is believed that the lower laminate porosity is due to the fact thatthe adhesive is applied as a discontinuous coating which createsamorphous elements of adhesive as opposed to spray fiberization whichcreates fine fibers that may not have as much resistance to air flow.

The starved slot coat adhesive process has been found to efficientlyplace adhesive on the surface of the facing material. For example, theadhesive generally only covers the fibers of the facing material anddoes not bridge the void areas in the material. In a spray process, onthe other hand, adhesive is applied everywhere on the substrate andtypically collects in the void areas on the facing. When collected inthe void areas, the adhesive does not substantially contribute tobonding the facing material to the elastic substrates.

In some applications, the starved coat adhesive process has been foundto only be applied to the surface of the facing material only on thefibers of the material and at substantially the high points of thematerial which are generally only the places on the material where thefacing can be bonded to the elastic filaments.

Another advantage to the process of the present disclosure in comparisonto spray processes is that since the adhesive is applied immediately tothe substrate as it is emitted from the slot extrusion die, no coolingor quenching of the adhesive occurs prior to being deposited on thematerial. As such, adhesives with higher or faster cure rates may beused.

In the past, slot coat processes have been disclosed in which a slot dieis used to dispense adhesive in order to form laminates. For instance,U.S. Pat. No. 5,750,444 to Jarrell, which is incorporated herein byreference, discloses a process for producing breathable laminates usinga slot die. In the '444 patent, the adhesive is described as forming aporous random fibrous web. The adhesive is used to attach together twoor more porous webs comprising woven or nonwoven materials to formlaminates that remain breathable even after application of the adhesivein between the materials.

In the process of the present disclosure, on the other hand, laminatesare formed in which elastic filaments are stretched and then bonded to afacing material. It was discovered that the starved slot coat process ofthe present invention was capable of adequately bonding the stretchedfilaments to the facing even at relatively low adhesive applicationrates. Also, it was unexpectedly discovered that the slot coat processas disclosed herein increased the porosity of the laminate in comparisonto spray processes. As will be described in more detail below, theincrease in porosity facilitates handling of the laminate in laterconverting processes.

Referring to FIGS. 1 and 2, one exemplary system and process forproducing laminates in accordance with the present invention isillustrated. In the embodiment shown in FIG. 1, the system may beconsidered a vertical filament lamination (hereinafter “VFL”) systemsince the elastic filaments are formed and stretched in a verticalarrangement. The system illustrated in FIGS. 1 and 2, however, is merelyfor exemplary purposes. It should be understood that the process of thepresent invention may be configured in a horizontal system in which thefilaments are cooled and stretched in a horizontal direction. Oneembodiment of a horizontal system, for instance, is illustrated in FIGS.1 and 2 of U.S. Pat. No. 6,057,024, which is incorporated herein byreference.

As shown in FIG. 1, however, the VFL system 11 is vertically configured.An extruder 15 is mounted for extruding continuous molten filaments 14downward from a die at a canted angle onto chilled positioning roller12. Chilled positioning roller 12 ensures proper alignment through theremainder of the system as it spreads the filaments. As the filamentstravel over the surface of chilled positioning roller 12, they arecooled and solidified as they travel towards and over the chilledsurface of chilled roller 13. The filaments then travel downward in an“s-shaped” progression to a roller 16 and then across the surface of aroller 17, a roller 18 and into the nip formed by nip roller 19 and niproller 20.

The continuous filaments 14 formed in the process may have any desirableshape. In one embodiment, for instance, the filaments may have aribbon-like shape. For instance, the filaments may have a width of fromabout 0.5 mm to about 1.5 mm in an unstretched state. The filaments allgenerally extend in the same direction and are generally parallel toeach other. The actual number of continuous filaments utilized in anyparticular process may vary depending upon the particularcharacteristics desired in the final product. For example, the array offilaments may total more than about 100 strands, such as more than about200 separate strands. For example, in one embodiment, the array offilaments may number from about 200 separate strands to as much as 2600separate strands. A greater or lesser number of strands, however, isalso possible.

As shown in FIG. 1, the extruder 15 may be positioned with respect tothe first roller 12 so that the continuous filaments meet the firstroller at a predetermined angle. In some embodiments, an angled, orcanted, orientation provides an opportunity for the filaments to emergefrom the die at an angle to the roll tangent point resulting in improvedspinning, more efficient energy transfer, and generally longer die life.This configuration allows the filaments to emerge from the die andfollow a relatively straight path to contact the tangent point on theroll surface. The angle between the die exit of the extruder and thevertical axis may be as little as a few degrees or as much as 90°. Forexample, the angle may be about 20°, about 35°, or about 45° away fromvertical.

The continuous filaments may be combined at the nip with various typesof facings. The facings, for example, may comprise nonwoven fabrics,woven fabrics including knitted fabrics, films, laminates, and the like.In the embodiment depicted in FIG. 1, a first non-woven spunbond facing22 and a second non-woven spunbond facing 24 are combined on opposingsurfaces of the continuous filaments to form a bonded laminate 25. Insome embodiments, only one facing may be used, and in other embodimentsit is possible to combine the elastic continuous filaments with three,four, or more layers of facing material.

Bonding of the facings to the continuous filaments is done with anadhesive material. In accordance with the present disclosure, theadhesive is applied to the facings using a slot extrusion die. Forinstance, as shown in FIGS. 1 and 2, a first slot extrusion die 23applies an adhesive to the nonwoven material 22, while a second slotextrusion die 53 applies an adhesive to the nonwoven material 24. Asillustrated, the nonwoven material 22 contacts the slot extrusion die23, while the nonwoven web 24 contacts the slot extrusion die 53 as theadhesive is being dispensed onto the nonwoven materials. To ensureproper contact, for instance, press rollers 60 and 62 are used.

In one embodiment, the adhesive application rates applied to thenonwoven materials can be relatively low. In fact, the adhesive rate isso low that the process can be referred to as a “starved” slot coatprocess. For example, in one embodiment, the adhesive is applied to eachof the nonwoven materials in an amount less than about 4.4 gsm, such asfrom about 0.5 gsm to about 3 gsm, such as from about 0.8 gsm to about2.5 gsm.

At such low add-on rates, the adhesive does not completely coat thenonwoven materials. Instead, the adhesive forms a discontinuous coating.For example, in one embodiment, the adhesive may form amorphous elementsplaced over the surface of the nonwoven material. Of particularadvantage, the adhesive primarily becomes applied to the nonwoven web atelevations on the web, which is the place where the web is capable ofbonding with the elastic filaments 14. More particularly, the adhesivetends to coat the top surface of the fibers on the web and fails tocollect or bridge the void areas in the web. Thus, little to no adhesiveis wasted creating maximum adhesive efficiency.

Although the adhesive forms a discontinuous coating, however, it shouldbe understood that the adhesive is applied in a substantially uniformmanner over the surface of the nonwoven material in terms of amount perarea.

In general, any suitable slot extrusion die may be used in the processof the present invention. For example, in one embodiment, a slotextrusion die commercially available from the Nordson Corporation ofWestlake, Ohio may be used. One example of a Nordson slot extrusion dieis disclosed in U.S. Pat. No. 5,750,444, which is incorporated herein byreference.

For exemplary purposes only, one embodiment of a slot extrusion diesystem is illustrated in FIGS. 6 and 7. As shown in FIG. 6, the systemincludes an adhesive supply 64 for receiving an adhesive material. Theadhesive supply may comprise a reservoir, may comprise a heatedreservoir, or may comprise an extruder as particularly shown in FIG. 6.The adhesive supply 64 feds an adhesive material into a line 66 to amultiple metering station 68. The metering station 68 is connected tothe slot extrusion die 23 for applying the adhesive material to thenonwoven material 22. More specifically, the metering station 68 isconnected to a plurality of lines 70A, 70B, 70C, 70D, 70E, 70F, 70G,70H, 70I, 70J, and 70K. The metering station 68, for instance, may beconfigured to supply adhesive to each of the lines which are in fluidcommunication with the slot extrusion die head 23. It should beunderstood, however, that more or less lines may be fed between themetering station 68 and the slot extrusion die 23.

In one embodiment, the multiple metering station 68 may include apumping device placed in association with each of the lines 70A-70K. Inthis manner, each of the lines may be operated independently of theothers. Thus, the amount of adhesive flowing through each line can varyfrom line to line. In other embodiments, however, each line may besupplied with equal amounts of adhesive.

In one embodiment, instead of containing a pumping device, each of thelines are fed directly from a screw extruder.

Referring to FIG. 7, a perspective view of the slot extrusion die 23 isshown with cut away portions for purposes of illustrating the interiorof the extruder. The slot extrusion die 23 includes a slot 72 throughwhich the adhesive material is emitted. In one embodiment, the slot 72is fed by multiple segments 74. Each segment 74 may be connected, forexample, to a corresponding line 70A-70K. By having multiple segments74, the amount of adhesive dispensed from each location on the slotextrusion die may be varied. Further, the effective width of the slot 72may be varied by turning on and off the outer lines.

In general, any suitable adhesive material may be dispensed ontononwoven materials in accordance with the present invention. In general,the adhesive may be, for instance, a hotmelt adhesive that is heatedprior to being applied to the nonwoven materials. The adhesive may havea viscosity exiting the slot extrusion die of from about 500 cp to about50,000 cp, such as from about 2,000 cp to about 20,000 cp. Thetemperature of the adhesive may vary depending upon the adhesive beingused. In one embodiment, however, the adhesive may be heated to atemperature of from about 250° F. to about 400° F., such as from about320° F. to about 350° F.

Particular adhesives that may be used in the present invention includevarious block copolymers, such as styrenic block copolymers. Such blockcopolymers include, for example, styrene-isoprene-styrene blockcopolymers, styrene-ethylene-butylene-styrene block copolymers,styrene-butadiene-styrene block copolymers, and the like.

In other embodiments, the adhesive material may comprise a randomcopolymer of a polyolefin. The polyolefin may be, for example, apolyethylene or a polypropylene.

In still other embodiments, an amorphous polyalphaolefin may be used. Instill other embodiments, a metallocene-catalyzed elastomeric resin, suchas a polyethylene or polypropylene resin can be utilized.

Commercially available adhesive materials may be obtained from Bostik,Inc., from the Dow Chemical Company, and from various other commercialsources. In some embodiments, the adhesive material may need to beheated prior to being applied to the nonwoven materials. The adhesives,for instance, may be heated to temperatures greater than 100° F., suchas from about 200° F. to about 400° F. In some embodiments, the adhesivemay be blended with a tackifier or may be blended with other elastomersas desired.

After the adhesive material is applied to the nonwoven webs 22 and 24,the webs are laminated to the elastic filaments 14 while the filamentsare in a stretched state. As shown in FIG. 1, a take-up roll 21 may beemployed for receiving and winding the bonded nonwovenmaterial/continuous filament/nonwoven material laminate 25 for storage.

FIG. 2 illustrates a side view of the VFL assembly, including supportframe 26 upon which the various components of the system are secured.Reference numerals are employed throughout the figures consistently toindicate the same components in the various views. As shown in FIG. 2,first outer facing roll 27 and second outer facing roll 28 provide thedesired facings 22 and 24 to the assembly. Support strut 29 holds thenip roller 20 in place. The rollers can be seen in side viewtransferring the continuous filaments downward to the nip, where thefilaments combine with the facings to form a bonded laminate.

Construction of the continuous filaments 14 will now be described ingreater detail including the manner in which the filaments are stretchedprior to being bonded to the nonwoven facings in accordance with thepresent disclosure. As shown in FIGS. 1 and 2, an elastomeric materialis extruded through a die head for initially forming the filaments.

FIG. 4 depicts an exemplary extruder die head 30 with capillary holes31. In FIG. 5, a close-up view of the die head is depicted. The patternand diameter of the capillary holes on the extruder die head may bevaried to provide filaments, with the appropriate spacing, withouthaving to utilize expensive combs, etc., to form a fabric having thecorrect elastic geometry. The distances d1 (distance between rows ofcapillary hole centers), d2 (distance between contiguous diagonalcapillary hole centers on opposing rows) and d3 (distance betweencontiguous capillary hole centers in the same row) may be varied,depending on the particular features desired in the final products. Forexample, various hole densities may be utilized in the present process.In a 12-filament/inch example, the distance between center lines of thedie holes (d1) may be approximately 2.12 millimeters. When a holedensity of 18-filaments/inch is utilized, the distance between die holecenter lines (d1) is approximately 1.41 mm.

The rollers that carry the continuous filaments are positioned andoperated so as to cause the continuous filaments to be stretched as theyvertically flow through the lamination system. When a number of rollersare employed, each successive roller turns in a direction opposite tothe immediately preceding roller so that the strands of continuousfilaments are handed off from roller to roller. In addition, the speedof each successive roller may be varied from the preceding roller so asto obtain the desired stretching and elongation characteristics. Forexample, any particular roller may operate at between 1 to 10 times, andmore, the speed of any preceding roller. Typically, a separatecontroller, such as a servomotor or a Turner drive, may be utilized toallow individual speed control for each roll and will drive eachindividual roll. When the speed is varied, successive rollers may turnat a faster rate to stretch or elongate the strands as they movedownwardly in the vertical process. In addition, the continuousfilaments are ultimately reduced to a fiber size of approximately 0.008to 0.040 inches in diameter, and in some cases to approximately 0.015 to0.020 inches in diameter.

The number of separate rollers used to convey the continuous filamentsto the bonding location may vary depending on the particular attributesdesired in the final product. In one particular embodiment, at leastfour rollers—a first chilled (or positioning) roller, a second chilledroller, a third unchilled roller, and a fourth unchilled roller—may beutilized. In another embodiment, only two chilled rollers may be neededbefore the continuous filaments are supplied to the laminator portion ofthe system which bonds the spunbond facing(s) to the continuousfilaments in a roller nip.

In certain embodiments, the rollers may be plasma coated to provide goodrelease properties. In other embodiments, the rollers may additionallybe grooved or channeled to ensure that the extruded continuous filamentsmaintain a proper separation between individual filaments as thefilaments pass over the surface of the rolls and flow through thesystem. In some embodiments, smooth rolls maybe used for one or all ofthe rolls. In the case where plasma-coated rolls are employed, thecontinuous filaments will not slip as much as they do on smooth,uncoated rolls. The plasma-coatings grips the strands and promoteincreased uniformity of distances between the continuous filamentstrands.

As suggested, any or all of the rollers may be chilled so as to morequickly quench, or harden, the continuous filaments as they areproceeding through the process. The chilled rolls may be chilled to acontrolled temperature of between about 45° F. and about 60° F.(typically about 45° F. or about 50°). Simultaneous quenching andstretching may be optimized depending on the particular stretchabilitycharacteristics desired in the final product.

In one particular embodiment, the series of rollers (or roller) may beenclosed within a sealed tower structure and conditioned air, with themoisture removed, may be utilized in order to control the chillingeffects of the rollers. For example, the chilled rolls may be chilled to50° F. or less relative to the controlled dewpoint. In such cases, thetemperature to which the rolls are chilled may be significantly lessthan 50° F., but with the conditioned air environment, the rolls mayremain at 50° F.

Other various mechanisms may be utilized to quench the continuousfilaments. For example, external air could be forced onto the fibers inorder to control the hardening of the fibers. In other embodiments, onelarge roll could be used with sufficient surface area in order to quenchthe fibers.

Maintaining a certain roller speed allows the appropriate degree ofelastic stretch to allow the puckers to form in the final laminate. Thepositioning chilled roller 12 normally turns at a surface speed in therange of about 3-10 feet per minute (“fpm”), while the firstvertically-placed chilled roller turns at about 5 to about 15 fpm. Thenext roller turns at about 7 to about 18 fpm, while the last roller,when applied and used, turns at a speed of about 12 to about 100 fpm.These ranges are approximate, and can vary depending upon the conditionsand final product configuration desired.

In one particular embodiment, the first roll may turn at approximately 5fpm;

the second roll at approximately 6 fpm; the third roll at approximately11 fpm; and the fourth roll at approximately 26 fpm. Another embodimentutilizes a first roll speed of 10 fpm; a second roll speed of 20 fpm; athird roll speed of 40 fpm; and a fourth roll speed of 80 fpm. In thisembodiment, the speed of the nip rollers is approximately 75 fpm. In afurther embodiment, the speed of the first chilled roll may beapproximately 400 fpm; the speed of subsequent rolls may beapproximately 750 fpm to stretch the continuous filaments; the speed ofthe composite material being formed at the nip rollers may beapproximately 1500 fpm; and the winding roller speed (to allowrelaxation and, thus, gathering of the spunbond facings) may beapproximately 700 fpm.

After passing through the series of rollers and becoming stretched, thecontinuous filaments are then bonded to the nonwoven materials 22 and 24using the slot extrusion die as described above. The nonwoven materials22 and 24 may be any suitable webs or laminates, including meltblownnonwoven webs, spunbond nonwoven webs, carded webs or even woven webs.In one particular embodiment, a polypropylene spunbond facing having abasis weight of approximately 0.4 oz/yd² may be employed.

The system employs nip rolls 19 and 20 to apply pressure to theadhesive-coated facing and the continuous filaments to result in thenecessary lamination. The outer facing is bonded together with thecontinuous filaments at a fairly high surface pressure, which may bebetween about 20 and 300 pounds per linear inch (“pli”). A typicalbonding pressure may be about 50 pli or about 100 pli.

The bonder, or nip roll, (sometimes referred to as “laminator”) sectionof the laminating apparatus performs the primary stretching on thecontinuous filaments. The speed ratio of the bonder or nip rollsrelative to the chilled rolls can be varied, and in most cases isbetween about 2:1 and 8:1 and in some is approximately 4:1 to 6:1.

After bonding of the facing(s) to the continuous filaments to form aspunbond/elastomeric continuous filament/spunbond laminate, the laminateis then allowed to relax and contract to an unstretched or lessstretched, condition. The laminate is then wound onto the take-up roll21 via a surface driven winder. The speed ratio of the winder relativeto the bonder rollers results in relaxation of the stretched continuousfilaments and a retraction of the laminate into a gathered state as thelaminate is wound onto the roll. For example, the winder speed to bonderroll speed may be approximately 0.3 to about 1.0, and may be from about0.5 to 1.0. The contraction of the continuous filaments results in agathered, stretchable laminate article where the outer facing(s) isgathered between the bonding points.

The overall basis weight of the laminate can vary, but in someapplications is between about 2 and about 4 ounces per square yard(“oz/yd²”). In one particular embodiment, the basis weight is betweenabout 2.85 and about 3.2 ozlyd².

Various types of compositions and various processing conditions may beutilized to form the elastic continuous filaments. For example, aKraton® brand elastic polymer may be fed into an extruder where thepolymer is melted at a controlled temperature of between about 2600 and460° F., and in certain instances at about 385°. In other embodiments,depending on the particular polymer employed, the melt temperature maybe approximately 470° F. to 480° F. The polymer is then extruded througha predetermined number of apertures in a die head in a generallydownward direction into separate continuous filaments at a pressure ofapproximately 300 to 4000 psi (typically from about 1500 to about 2000psi). As explained below, various die hole configurations may beutilized in the present invention.

One particular class of polymers that may be utilized in the presentprocess is the Kraton® G series of polymers distributed by ShellChemical Company (now available from Kraton Products U.S.-LLC). VariousKraton® polymers may be utilized.

However, the present invention is not limited to this or any particularpolymer or material from which to form the continuous filaments. Forexample, various materials, including the following, may be used:polypropylene, polyethylene, polyesters, polyethylene terephthalate,polybutane, polymethyldentene, ethylenepropylene co-polymers,polyamides, tetrablock polymers, styrenic block copolymers,polyhexamethylene adipamide, poly-(oc-caproamide),polyhexamethylenesebacamide, polyvinyls, polystyrene, polyurethanes,thermoplastic polymers, polytrifluorochloroethylene, ethylene vinylacetate polymers, polyetheresters, polyurethane, polyurethaneelastomerics, polyamide elastomerics, polyamides, viscoelastic hot meltpressure sensitive adhesives, cotton, rayon, hemp and nylon. Inaddition, such materials may be utilized to extrude single-constituent,bi-constituent, and bi-component filaments within the scope of thepresently described invention.

Other exemplary elastomeric materials that may be used includepolyurethane elastomeric materials such as those available under thetrademark ESTANE from B. F. Goodrich & Co., polyamide elastomericmaterials such as those available under the trademark PEBAX from theRilsan Company, and polyester elastomeric materials such as thoseavailable under trade designation HYTREL from E. I. DuPont De Nemours &Company.

However, the invention is not limited to only such elastomericmaterials. For example, various latent elastic materials such as theArnitel-brand polymers may be utilized to provide the necessaryelasticity characteristics to the continuous filaments.

Likewise, the above-referenced materials, and others, may be utilized informing the outer facings of the presently described laminate. Inparticular, various webs may be utilized that are formed fromelastomeric or nonelastomeric fibers. Various polyester elasticmaterials are, for example, disclosed in U.S. Pat. No. 4,741,949 toMorman et al., which is incorporated herein in its entirety by referencethereto. Other useful elastomeric polymers also include, for example,elastic copolymers of ethylene and at least one vinyl monomer such as,for example, vinyl acetates, unsaturated aliphatic monocarboxylic acids,and esters of such monocarboxylic acids. The elastic copolymers andformation of elastomeric fibers from these elastic copolymers aredisclosed in, for example, U.S. Pat. No. 4,803,117, which is alsoincorporated herein in its entirety by reference thereto.

Various processing aids may also be added to the elastomeric polymersutilized in the present invention. For example, a polyolefin may beblended with the elastomeric polymer (e.g., the A-B-A elastomeric blockcopolymer) to improve the processability of the composition. Thepolyolefin should be one which, when so blended and subjected to anappropriate combination of elevated pressure and elevated temperatureconditions, is extrudable in blended form with the elastomeric polymer.Useful blending polyolefin materials include, for example, polyethylene,polypropylene and polybutene, including ethylene copolymers, propylenecopolymers and butene copolymers. A particularly useful polyethylene maybe obtained from the U.S.I. Chemical Company under the trade designationPetrothene NA 601 (also referred to herein as PE NA 601 or polyethyleneNA 601). Two or more of the polyolefins may be utilized. Extrudableblends of elastomeric polymers and polyolefins are disclosed in, forexample, U.S. Pat. No. 4,663,220, which is incorporated herein in itsentirety by reference thereto.

Referring to FIG. 5, an alternative embodiment of a process forproducing laminates in accordance with the present invention is shown.In this embodiment, the VFL system 111 is also vertically configured. Asstated above, however, horizontally configured systems are equallyapplicable to the present invention.

As shown in FIG. 5, an extruder 115 is mounted for extruding continuousmolten filaments 114 downward from a die at a canted angle onto chilledpositioning roller 112. Chilled positioning roller 112 ensures properalignment through the remainder of the system as it spreads thefilaments. As the filaments travel over the surface of chilledpositioning roller 112, they are cooled and solidified as they traveltowards and over the chilled surface of chilled roller 113. Thefilaments then travel downward towards the laminator section of thesystem comprising a nip formed by a nip roller 119 and a nip roller 120.

The continuous filaments are combined at the nip with various types offacings. In the embodiment depicted in FIG. 5, a first nonwoven spunbondfacing 122 and a second nonwoven spunbond facing 124 are combined onopposing surfaces of the continuous filaments to form a bonded laminate125.

In accordance with the present invention, a slot extrusion die 123 isused to apply an adhesive material to the facing 122, while a slotextrusion die 153 is used to apply an adhesive material to the spunbondfacing 124.

In the embodiment illustrated in FIG. 5, only two chill rolls are usedas opposed to the greater number of chill rolls shown in FIG. 1.

As stated above, the use of a starved slot coat extrusion process asdescribed above provides various advantages. For example, unexpectedlyit was discovered that the starved slot coat process decreases theporosity of the resulting laminate, even at relatively low adhesiveapplication rates. For example, laminates as shown in FIG. 1 can beproduced having an air permeability of less than about 400 cfm per ft²,such as less than about 350 cfm per ft², and, in one embodiment, may beless than about 300 cfm per ft². In other embodiments, the airpermeability of the laminate may be less than about 250 cfm per ft²,such as less than about 230 cfm per ft². For laminates only containing asingle facing material laminated to the continuous filaments, the airpermeability may be less than about 300 cfm per ft². For example, inapplications particularly where the facing comprises a spunbond web, theair permeability of the composite material may be less than about 250cfm per ft², such as less than about 230 cfm per ft².

Having a lower porosity facilitates handling of the material in laterconverting processes. For example, such laminates are well suited foruse in the construction of absorbent articles, such as diapers. Duringthe production of a diaper, the elastic laminate typically needs to becut, manipulated and bonded into place. During these process steps,vacuum is often used in order to convey and move the material. Loweringthe porosity of the material greatly facilitates the ability tomanipulate the material using a vacuum or suction force. Ultimately,materials made according to the present invention may be processed athigher machine speeds greatly increasing throughput.

The present invention may be better understood with respect to thefollowing examples.

EXAMPLES

Testing Procedures

During the examples that follow, the following tests were performed onthe samples that were produced.

Porosity was measured using procedure number STM 3801. Porosity wasmeasured using a Frazier air permeability tester. The units are cubicfeet per minute per square foot (cfm per ft²).

Elongation was measured test procedure number STM 529-W. Elongation maybe tested using any suitable tensile testing equipment, such as thoseavailable from the Syntech Corporation of Cary, N.C., or from theInstron Corporation of Canton, Mass.

In a Peel Test, a laminate is tested for the amount of force needed topull the layers of the laminate apart. The peel strength was measuredusing testing procedure number STM 751-W. The samples were tested in thecross machine direction. Any suitable tensile testing equipment may beused in order to perform the procedure.

Example No. 1

The following example was performed in order to determine the effect ofthe slot coat extrusion process on the porosity of nonwoven laminates.

In this example, two spunbond webs were laminated together. The spunbondwebs used were made from polypropylene and had a basis weight of 0.42osy.

Nine samples were produced and tested. In the first three samples, anadhesive was sprayed between the spunbond webs using a uniform fiberdepositor (“UFD”) available from ITW Dynatec of Hendersonville, Tenn.under the name Dynafiber™ UFD nozzle. The uniform fiber depositor hadone inch wide nozzles and contained fourteen capillaries per nozzle. Theadhesive used in conjunction with the spray device was adhesive numberH2808-07 obtained from Bostik, Inc. and is an SIS-based adhesive. Thisparticular adhesive is well suited for use in spray processes.

When spraying the adhesive between the spunbond webs, two differentuniform fiber depositors were used that were positioned adjacent to eachweb.

In the remaining six samples produced, the spunbond webs were laminatedtogether using a slot extrusion die. In particular, the slot extrusiondie was model number BC62 obtained from the Nordson Corporation. Theslot on the slot extrusion die has a 0.15 inch gap and was 20 incheswide.

The adhesive used in conjunction with the slot extrusion die wasHX9375-01 obtained from Bostik, Inc., which is a polyolefin copolymerblend. This particular adhesive is somewhat stiff and therefore does notalways produce a uniform spray pattern. The adhesive is well suited foruse with slot extrusion dies.

The adhesive was heated prior to being applied to the nonwoven websusing the slot extrusion die. In sample numbers 4 and 5 below, theextruder was heated to a temperature of from about 340° F. to about 345°F. In the remaining samples, however, the extruder was heated to atemperature of from about 355° F. to about 360° F.

The adhesive add-on rates were the same for both the spray process andthe slot extrusion die process, and range from 1 gsm to 3 gsm.

The following results were obtained: TABLE NO. 1 Adh Adh Adhesive NipNip Sample How Head #1 Head #2 Total Pressure Speed Porosity No. AppliedGSM GSM GSM PLI FPM CFM 1 Spray 0.5 0.5 1 100 1000 474 2 Spray 1 1 2 1001000 424 3 Spray 1.5 1.5 3 100 1000 429 4 Slot Coat 1 n/a 1 40 1000 4305 Slot Coat 2 n/a 2 40 1000 433 6 Slot Coat 3 n/a 3 40 1000 407 7 SlotCoat 1 n/a 1 40 1000 391 8 Slot Coat 2 n/a 2 40 1000 339 9 Slot Coat 3n/a 3 40 1000 320

As shown above, laminates formed using the slot extrusion die had alower porosity than the laminates produced using the spray device.

Example No. 2

In this example, elastic laminates were produced according to thepresent invention and tested for various properties. In order to producethe laminates, a process similar to the one illustrated in FIG. 5 wasused. Specifically, a VFL process was used that contained two chillrolls. The laminates produced included two layers of material, namely aspunbond facing adhered to continuous elastic filaments.

The facing comprised a polypropylene spunbond web having a basis weightof 0.4 osy.

The elastic continuous filaments were made from elastomeric blockcopolymers. Specifically, the elastic filaments were made using KRATONG2838 polymer available from Kraton products.

The same two adhesives identified in Example No. 1 were applied to thespunbond facing to produce the different samples. In particular, in thefirst five samples, adhesive HX9375-01 available from Bostik, Inc. wasused, while in the remaining seven samples, adhesive number H2808-07also obtained from Bostik, Inc. was used. The adhesive was applied tothe spunbond web in amounts from 1.5 gsm to 2.5 gsm. The elasticfilaments were laminated to the spunbond web at a basis weight of 10 gsmand were stretched 5.6 percent when attached. The temperature of theadhesive was varied depending upon the sample.

In one sample, Sample No. 12 below, the adhesive was applied using theuniform fiber depositor as described in Example 1 for purposes ofcomparison.

The following results were obtained: TABLE NO. 2 Stretch to Stop Temp ofAdhesive Nip Nip (at 2000 Load @ Sample Extruder Total Pressure Speedgrams) 50% Porosity Peel, CD No. Adhesive ° F. GSM PLI FPM % grams CFMgrams 1 HX9375-01 345 1.5 100 800 266 328 239 1665 2 HX9375-01 345 2.0100 800 265 317 245 2352 3 HX9375-01 365 1.5 100 800 282 330 237 1855 4HX9375-01 365 2.0 100 800 266 322 224 2248 5 HX9375-01 365 2.5 100 800252 319 238 3305 6 H2808-07 345 1.5 100 800 295 292 254 443 7 H2808-07345 2.0 100 800 294 307 241 479 8 H2808-07 345 2.0 100 800 284 306 226517 9 H2808-07 365 1.5 100 800 294 305 250 571 10  H2808-07 365 2.0 100800 302 312 245 603 11  H2808-07 365 2.5 100 800 298 315 238 550 12 H2808-07 365 2.5 100 800 265 298 266 2981 (control) (with spray device)

As shown above, the samples made according to the present invention hada much lower porosity than the control sample. As shown in the abovetable, the peel strength of samples made with the H2808-07 adhesive wasgenerally less than the peel strength of the laminates made with theHX9375-01 adhesive. As explained in Example No. 1 above, the HX9375-01adhesive is better suited for use with a slot extrusion die.

These and other modifications and variations to the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention, which ismore particularly set forth in the appended claims. In addition, itshould be understood that aspects of the various embodiments may beinterchanged both in whole or in part. Furthermore, those of ordinaryskill in the art will appreciate that the foregoing description is byway of example only, and is not intended to limit the invention sofurther described in such appended claims.

1. A method for producing a composite material comprising: extruding continuous filaments, the filaments comprising an elastomeric material; stretching the continuous filaments; applying an adhesive material to a first side of a facing material, the adhesive material being applied to the facing material from a slot extrusion die, the adhesive material forming a discontinuous coating comprising amorphous elements of the adhesive material; and laminating the stretched continuous filaments to the first side of the facing material after the adhesive material has been applied.
 2. A method as defined in claim 1, wherein, in terms of basis weight per area, the adhesive material is applied in a substantially uniform manner over the first side of the facing material.
 3. A method as defined in claim 1, further comprising the step of applying an adhesive material to a first side of a second facing material, the adhesive material being applied to the second facing material from a slot extruder; and laminating the stretched continuous filaments to the first side of the second facing material, the stretched continuous filaments being positioned in between the first facing material and the second facing material to form the composite material, the composite material having a porosity of less than about 300 cfm per ft².
 4. A method as defined in claim 3, wherein the first facing material and the second facing material comprise spunbond webs.
 5. A method as defined in claim 1, wherein the slot extrusion die defines a slot through which the adhesive material is emitted, and wherein the first side of the facing material contacts the slot as the adhesive material is applied to the facing material.
 6. A method as defined in claim 1, wherein the adhesive material is applied to the first side of the facing material in an amount less than about 4.4 gsm.
 7. A method as defined in claim 1, wherein the adhesive material is applied to the first side of the facing material in an amount from about 0.5 gsm to about 3 gsm.
 8. A method as defined in claim 1, wherein the adhesive material comprises a styrenic block copolymer, a random copolymer of a polyolefin, an amorphous polyalphaolefin, or mixtures therof.
 9. A method as defined in claim 1, wherein the adhesive material comprises a hotmelt adhesive.
 10. A method as defined in claim 1, wherein the adhesive material has a viscosity of from about 500 cp to about 50,000 cp as the material is being applied to the first side of the facing material.
 11. A method as defined in claim 1, wherein the continuous filaments move vertically downward as they are formed and laminated to the first facing material.
 12. A method as defined in claim 1, further comprising the step of relaxing the composite nonwoven material after the continuous filaments are laminated to the facing material.
 13. A method as defined in claim 1, further comprising the step of applying an adhesive material to a first side of a second facing material, the adhesive material being applied to the second facing material from a slot extrusion die, the adhesive material forming a discontinuous coating comprising amorphous elements of the adhesive material; and laminating the stretched continuous filaments to the first side of the second facing material after the adhesive material has been applied to the second facing material, the stretched continuous filaments being positioned in between the first facing material and the second facing material to form the composite nonwoven material.
 14. A method as defined in claim 1, wherein the continuous filaments are stretched by being conveyed over at least one roller.
 15. A method as defined in claim 1, wherein the facing material comprises a nonwoven web having a basis weight of from about 0.2 osy to about 1.5 osy.
 16. A method as defined in claim 15, wherein the nonwoven web comprises a spunbond web.
 17. A method as defined in claim 1, wherein the elastomeric material used to make the filaments comprises an elastomer selected from the group consisting of elastic polyesters, elastic polyurethanes, elastic polyamides, elastic copolymers of ethylene and at least one vinyl monomer, elastic metallocene-catalyzed polyolefins, and elastic block copolymers.
 18. A method as defined in claim 1, wherein the resulting composite material has at least three layers and has an air permeability of less than about 350 cfm per ft².
 19. A method as defined in claim 1, wherein the resulting composite material comprises only two layers including the layer of continuous filaments in the facing material, the facing material comprising a spunbond web, the composite material having an air permeability of less than about 400 cfm per ft².
 20. A composite elastic material comprising: elastic continuous filaments extending generally in the same direction, the continuous filaments comprising an elastomeric material; a nonwoven web having a first side and a second side, the first side of the nonwoven web being laminated to the elastic continuous filaments, the elastic continuous filaments being laminated to the nonwoven web in a stretched state such that the nonwoven web gathers when the elastic continuous filaments are relaxed; and an adhesive material bonding the elastic continuous filaments to the first side of the nonwoven web, the adhesive material comprising a discontinuous coating on the first side of the nonwoven web, the discontinuous coating comprising amorphous elements of the adhesive material, the adhesive material being present on the nonwoven web in an amount less than about 4.4 gsm.
 21. A composite elastic material as defined in claim 20, wherein the adhesive material is present on the first side of the nonwoven web in an amount from about 0.8 gsm to about 3 gsm.
 22. A composite elastic material as defined in claim 20, wherein the adhesive material comprises a styrenic block copolymer, a random copolymer of a polyolefin, an amorphous polyalphaolefin, or mixtures therof.
 23. A composite elastic material as defined in claim 20, wherein the adhesive material comprises a hotmelt adhesive.
 24. A composite elastic material as defined in claim 20, further comprising a second nonwoven web having a first side and a second side, the first side of the second nonwoven web being laminated to the elastic continuous filaments such that the elastic continuous filaments are positioned in between the first nonwoven web and the second nonwoven web; and an adhesive material bonding the elastic continuous filaments to the first side of the second nonwoven web, the adhesive material comprising a discontinuous coating on the first side of the second nonwoven web, the discontinuous coating comprising amorphous elements of the adhesive material, the adhesive material being present on the first side of the second nonwoven web in an amount of less than about 4.4 gsm.
 25. A composite elastic material as defined in claim 20, wherein the nonwoven web comprises a spunbond web having a basis weight of from about 10 gsm to about 20 gsm.
 26. A composite elastic material as defined in claim 20, wherein the elastomeric material used to form the continuous filaments comprises an elastomer selected from the group consisting of elastic polyesters, elastic polyurethanes, elastic polyamides, elastic copolymers of ethylene and at least one vinyl monomer, elastic metallocene-catalyzed polyolefins, and elastic block copolymers.
 27. A composite elastic material as defined in claim 24, wherein the composite elastic material has an air permeability of less than about 350 cfm per ft².
 28. A composite elastic material as defined in claim 20, wherein the adhesive material is present on the first side of the nonwoven web in a substantially uniform manner in terms of amount per unit area.
 29. A composite elastic material as defined in claim 20, wherein the composite elastic material only comprises two layers including a layer of the continuous filaments and the nonwoven web, the nonwoven comprising a spunbond web, the composite elastic material having an air permeability of less than about 400 cfm per ft².
 30. A composite elastic material as defined in claim 20, wherein the adhesive only coats the surface fibers of the nonwoven web and does not appreciably deposit in any pores on the nonwoven web. 